Multipurpose gasoline additive



United States Patent Ofilice v 3,3 1.,e4s Patented Oct. 17, 19673,347,645 MULTIPURPOSE GASOLINE ADDITIVE Gerhard J. Pietsch, Elizabeth,and John D. Turner, North Plainfield, N.J., assignors to Esso Researchand Engineering Company, a corporation of Delaware No Drawing. FiledDec. 20, 1963, Ser. No. 332,233

Claims. (Cl. 44-63) This invention concerns a multipurpose gasolineadditive package, and more particularly, a multipurpose additive packagethat does not significantly promote dispersions of water in gasoline.

Various nitrogen-containing derivatives of high molecular weightalkenylsuccinic anhydride have become known as sludge dispersants forlubricating oils and are described in US. Patents 3,018,247, 3,018,250and 3,018- 291. A particularly effective derivative of this general typeis prepared by reacting an alkenylsuccinic anhydride with a polyamine,e.g., tetraethylene pentamine, as described in Australian patentapplication No. 63,803, filed Aug. 22, 1960. Recently, it was found thatadditives of the last-named type can be further improved in their sludgedispersing effectiveness in lubricating oil by converting the polyamineinto a 2-imidazoline which is condensed with the alkenylsuccinicanhydride. These additives are also useful in gasoline. They reducecrankcase slude and piston varnish. They are good corrosion inhibitorsand improve the stability of gasoline in storage.

Although these additives are effective in gasoline, there is a seriousproblem that is occasioned in their use. During transport and storage,gasoline commonly contacts water bottoms. Ordinarily, in storage twodistinct phases separate: a clear gasoline phase and a water layer.

The additives described above promote a dispersion of water in thegasoline. This is undesirable for many reasons, for example, theentrained water commonly causes carburetor icing that results in enginepower losses and engine stalling.

' In addition, these dispersant additives promote a gasoline-in-wateremulsion; the resulting creamy additive gasoline-in-water emulsion isundesirable in that it results in a waste of gasoline and additive andpresents problems in disposing of the water bottoms containing highconcentrations of gasoline.

It is therefore an object of this invention to provide a multipurposeaddditive package (containing the abovedescribedimidazoline-alkenylsuccinic anhydride condensation products) thateilects an essentially complete separation of gasoline and water.

The object of this invention is attained by using theimidazoline-alkenylsuccinic anhydride in combination with a benzenesulfonic acid and an ethoxylated dimeric acid.

The additive package comprises a multipurpose additive prepared bycondensing an imidazoline with an alkenylsuccinic anhydride incombination with a benzene sulfonic acid and an ethoxylated dimericacid. In a preferred embodiment of this invention, a solvent oil isincluded in the package.

The additive that is active in reducing crankcase sludge and ininhibiting corrosion is a derivative of an alkenylsuccinic anhydride andhas the following formula:

wherein R and R are selected from the group consisting of hydrogen andhydrocarbon radicals provided that at least one of said R and R is ahydrocarbon radical and the total number of carbon atoms in R and Rcombined is about 40 to 7250; R" is an aliphatic hydrocarbon radical of1 to 30 carbon atoms; n is 2 to 3 and m is 0 to 10.

The alkenylsuccinic anhydrides can be readily prepared by reactingmaleic anhydride with an organic compound having a double bond at an endto thereby give compounds of the general formula:

wherein R and R can be hydrogen, or hydrocarbon radicals which can beeither substituted (e.g., chlorinated or sulfurized) or unsubstituted,including aliphatic, acyclic, aromatic radicals, etc., although at leastone of said R and R must be a hydrocarbon group. The total of R and Rwill generally contain 40 to 250, preferably to 120, carbon atoms.Primarily because of its ready avail ability and low cost, the alkenylportion of the molecule is preferably obtained by reacting with themaleic anhydride a polymer of a C to C monoolefin, said polymergenerally having a molecular weight of about 700 to 3,000 e.g., about800 to 1,300. A particularly preferred example of such an olefin polymeris polyisobutylene. In this case, R will be hydrogen, while R will bethe radical:

where n is determined by the molecular weight of the polyisobutylenebeing used.

The preparation of alkenylsuccinic anhydride is known in the art, forexample, see US. 3,018,250, column 3, lines 57 to 71, Example 1.Generally, about equal molar proportions of maleic anhydride and theolefinic material are simply heated together. Inert solvents, such astoluene, xylene, etc., can be used as diluents to lower the viscosity ofthe reaction product in the case of a very viscous alkenyl material topermit easier subsequent filtration of the reaction product. The solventcan then be later removed by evaporation. Or, in some cases where thediluent is high-boiling and not objectionable in the final end use, thediluent can be simply left in the reaction product. This preparation ofthe alkenylsuccinic anhydride is illustrated by the following equation:

wherein R and R have the meanings previously given.

The imidazoline that is reacted with the alkenylsuccinic anhydride canbe prepared by a condensation reaction of a carboxylic acid and analiphatic polyamine as illustrated by the following equation using amonocarboxylic acid:

wherein R is a C to C preferably a C to C aliphatic hydrocarbon radical,either saturated or unsaturated, of a fatty acid; It is 2 or 3; and m isto preferably 0 to 3. In place of the monocarboxylic acid illustrated bythe above equation, dicarboxylic acids can also be used, in which caseboth carboxylic acid groups can react with a terminal amine groups oftwo separate polyamine molecules.

Examples of operable acids include acetic acid, fu-maric acid, capricacid, adipic acid, lauric acid, oleic acid, linoleic acid, stearic acid,etc. Acetic acid is particularly preferred since it forms an imidazolinewith a minimum of carbon atoms. Thus, since the acid does not appear tocontribute very much to the final product, aside from permitting theimidazoline formation, the lower the molecular weight of the acid themore effective the final product appears to be in sludge dispersingability per Weight of final product. In other words, the higher acidsappear to contribute bulk without substantial improvement, so as tolessen the effectiveness of the final product on a weight basis,although such higher acids are operable.

Examples of the polyamines operable in the above reaction includediethylene triamine, tetraethylene pent amine, octaethylene nonamine,tetrapropylene pentamine, etc.

The imidazoline-forming reaction between the acid and the polyamine canbe carried out by simple mixing of substantially stoichiometricproportions of said acid and polyamine, followed by heating to refluxand the removal of the water of condensation. An invert solvent, such asheptane or toluene, can be used, if desired, as a water-entraining agentin order to aid in the removal of the water of reaction. The solvent canthen be removed later by evaporation.

The third step in forming the product of the present invention involvesthe reaction of the imidazoline with the alkenylsuccinic anhydride. Thisreaction is represented by the following equation:

wherein R, R, R", m and n have the meanings previously mentioned. Thisthird and last step of the reaction represented above is preferablycarried out using an equi-molar proportion of the two reactants byheating to refluxing and removing the water of condensation. An inertsolvent can again be used, as in the first two stages, in preparing thefinal product.

As mentioned before, the above-described additives promote a water hazein gasoline and an additive-gasoline emulsion in water.

Many known dehazing additives proved to be unsuccessful in dissipatingthe water haze in gasoline. Although some tended to clear the gasoline,the results were not satisfactory. Likewise, many known demulsifierswere unsuccessful in breaking the additive and gasoline in wateremulsion. In short, many combinations of dehazers and dernulsifiersproved to be unsatisfactory.

It has now been discovered that a particular combination of additivescauses a complete separation of gasoline and water. Neither additiveused alone satisfactorily clears either the gasoline or the water phase.However, when used in combination, the additives effect an essentiallycomplete separation of Water and gasoline.

The combination of additives employed to cause complete separation ofgasoline and water comprises a benzene sulfonic acid and an ethoxylateddimeric acid.

Suitable benzene sulfonic acids include alkyl benzene sulfonic acidswherein the alkyl group contains from 1 to 30 carbon atoms, andpreferably from 8 to 16 carbon atoms. It is preferred that the alkylgroup be branchchained and unsubstituted, however, straight-chainedalkyl groups containing substituent groups are believed to besatisfactory. The most preferred alkyl benzene sulfonic acids are thosewherein the alkyl group is unsaturated, e.g., dodecyl benzene sulfonicacid. These additives can be prepared by methods well known to the art.

The ethoxylated polymeric acid is prepared by reacting a polyalkyleneglycol with a polymeric carboxylic acid. Suitable carboxylic acidsinclude those having from 14 to 60 carbon atoms per carboxyl group;preferred acids include dilinoleic and trilinoleic acids. A verysatisfactory acid for use in preparing the ethoxylated polymeric acid isa mixture of polymerized fatty acids predominanting in trilinoleic acid.Such acids may be produced as by-products still-residues in themanufacture of sebacic acid by the distillation of castor oil. Theresidue is an amber-colored viscous residue containing long chainpolycarboxylic acids, having an acid number between and 165, an iodinenumber of between 30 and 60, and is the nonvolatile material remainingfrom vacuum distilling at 270 C. under 4 mm. Hg pressure the by-productacids obtained in the preparation of sebacic acids from castor oil inthe presence of an alkali. These materials are fully described in US.Patents 2,471,230, 2,267,269, and 2,470,849.

The residue comprises monomers, dimers, trimers, and higher polymers inthe ratio of from about 45 to 55 wt. percent of a monomers and dimersfraction having a molecular weight in the range of from about 300 to600, and from about 55% to 45 wt. percent of a higher polymer fractionhaving a molecular weight above 600.

This residue is reacted with a polyalkylene glycol to obtain theadditive employed in this invention. Polyethylene glycol is preferredbut polyglycols made from alkylene compounds having from 2 to 7 carbonatoms are suitable. The polyalkylene glycol should have a molecularweight of from 200 to 800, preferably 300 to 500.

The polymeric carboxylic acid is reacted with the polyalkylene glycol(stoichiometric amounts) in the presence of from about 0.2 to 0.4 wt.percent of an alkaline catalyst, e.g. soda ash, sodium hydroxide, or thelike. The catalyst should be added after the temperature of thereactants has been rapidly raised to about 300 F. After the catalystaddition, the temperature should then be raised to about 500 F. and keptthere for from 2 to 4 hours.

In a preferred embodiment of this invention, the additive packagecontains a solvent oil to reduce the amount of deposits in the intakemanifold.

The oil should boil in the range of from 350 to 800 F. at mm. of Hg andpreferably from 400 F. to 700 F. The oil should have a viscosity withinthe 'range of from 45 SSU/210 F. to 150 SSU/210 F. Typical inspectionfor an oil of this type is as follows:

TABLE I Gravity, API 28.8 Sulfur, wt. percent 0.40 Neutralization No.D974 0.02 Aniline point, F. 273.5 ASTM distillation, 10 mm. Hg vacuum:

IBP, F. 353

10% Point, F. 464

50% Point, F. 534

90% Point, F. 626

FBP, F. 694 Conradson Carbon Residue 0.1 Vis/210 F., SSU 60.7

The imidazoline alkenylsuccinic anhydride condensation product isemployed in gasoline in a small amount sufficient to reduce enginedeposits. The amount needed varies, depending upon the .gasoline, thepresence of other additives etc., but generally in the range of from 1to 500 pounds per 1,000 barrels of gasoline, and preferably, in therange of from to 100.

The combination of benzene sul'fonic acid and the ethoxylated dimericacid is employed in a minor amount suflicient to effect an essentiallycomplete separation of water and gasoline. This amount varies, dependingupon the particular water bottoms contacted. The combination should beemployed in gasoline in a concentration of from 10 to 120 p.p.m. Alarger amount can be employed, but is usually not necessary. A preferredrange and a range that is suitable for most purposes is from to 40p.p.m.

The combination of benzene sulfonic acid and the ethoxylated dimericacid is operable over a wide range of relative proportions. The benzenesulfonic acid should constitute from to 90 wt. percent of thecombination, preferably 45 to 75%.

The imidazoline alkenylsuccinic anydride condensation product, thebenzene sulfonic acid and the ethoxylated dimeric acid are viscousmaterials and can be blended prior to being added to gasoline byblending at a temperature of about 130 to 150 F. to form an essentiallyhomogenous blend. This blend should comprise from 91 to 93 wt. percentof the condensation product and from 9 to 7 wt. percent of thecombination of benzene sulfonic acid and the ethoxylated dimeric acidwherein the sulfon-ic acid constitutes from 30 to 90 wt. percent,preferably 45 to 75 wt. percent of the combination.

If intake valve deposits are encountered, one may dissolve theabove-described blend in a solvent oil such as that oil described inTable I. The resulting gasoline composition should contain from 0.1 to 1vol. percent, preferably 0.5 vol. percent, of the oil to reduce intakevalve deposits.

It is sometimes desirable to employ a solvent containing at least 50%aromatics, e.g. toluene or the like, rather than the aliphatic solventdescribed in Table 1. The aromatic solvents are not as effective inreducing deposit formation, but the additive blend of this invention ismore stable in the aromatic solvents. Since the additive blend can bemore easily dissolved in gasoline if it is in a solvent solution, onefinds an advantage in using the aromatic solvent where thesolvent-additive solution must be stored prior to admixture withgasoline; no precipitation occurs from the aromatic solvent solutionwhereas some is observed with the use of an aliphatic solvent.

The gasolines to which the additive blend of the invention is added mayalso contain other additives such as lead alkyl antiknock additives,anti-icing additives, e.g. hexylene glycol and the like, and otheradditives commonly employed in fuels.

The following specific additives were tested to illustrate the eflicacyof the instant invention:

Additive A Part 1.Alkeny1succinic anhydride was prepared as follows:

2700 grams of polyisobutylene of 1,1000 molecular weight (Staudinger)was added to a flask containing 270 grams of maleic anhydride. Thesereactants were then heated at a temperature of about 485 F. for about 19hours, cooled to about 60 C., diluted with about 50 Wt. percent toluene,based on the total weight of reactants, filtered through Hyflo and thenthe toluene Was evaporated overnight on a steam bath. The toluene wasused simply to reduce the viscosity of the reaction product to permiteasier filtering. The recovered reaction product was a tacky material ofamber color, and had a saponification number of 67.2 mg. KOH/gm. ofreaction product.

Part 2.An imidazoline was prepared as follows:

300 grams (5 moles) of glacial acetic acid was added to a flaskcontaining 945 grams (5 moles) of tetraethylene pentamine and gm.xylene. The contents of the flask were heated to reflux at atmosphericpressure and the water of reaction was collected in a Dean-Stark trapunil 152 gm. of water had been so collected. The refluxing took about 16hours. The product was then cooled. The water-entraining agent, i.e.Xylene, was stripped from said product with N blowing while heating on asteam bath. The resulting imidazoline was a dark, amber-colored oil.

Part 3.The alkenylsuccinic anhydride and imidazoline were reacted asfollows:

50.2 grams of the imidazoline product of Part 2 above ing with nitrogenwhile heating on a steam bath. The

final product was a dark-colored, viscous material having a reddishcast.

Additive B A commercial grade of dodecylbenzene sulfonic acid wasemployed in the tests described hereinafter.

Additive C The preferred ethoxylated dimeric acid of this invention ismade by reacting polyethylene glycol having a molecular weight of 400with a residue prepared as described in US. Patent 2,471,230, specialattention being directed to C01. 1, line 46 through column 2 line 10.See also US. 2,723,233, where the use of the material is described.

66.93 grams of the residue (molecular weight about 1200) and 33.07 gramsof polyethylene glycol having a molecular weight of 400 were chargedinto a flask and air-blown. The temperature was rapidly raised to 300 F.and 0.025 weight percent soda ash was added. The temperature of thereactants was then raised to 500 F. and maintained at this temperaturefor approximately 2 /2 hours.

The above-described additives were tested in a gasoline of the followingspecification.

7 TABLE II Base gasoline inspections ASTM Distillation, Method D-86:

20% Boiling point, F 131 55% Boiling point, F 212 96% Boiling point, F356 Final boiling point, F. 395 ASTM Gum, mg./l ml. 2 ASTM Breakdowntime, min. 300 FIA Analysis:

Vol. percent saturates 50 Vol. percent olefins 28.8 Vol. percentaromatics 21.2 Tetraethyl Lead, cc./ gal. 1.22 Research octane No. (RON)94.3 Motor octane No. (MON) 84.8

Exmnple 1.-4.5 ml. of alkaline water bottoms were added to a 450 ml.sample of the gasoline described in Table II. The blend was thenagitated in a Waring Blendor for one minute at 3600 r.p.m. A water hazeformed in the gasoline, but the water separated from the gasoline soonafter the agitation was stopped.

Example 2.A solution Was prepared consisting of one gram of Additive Ain 100 ml. of toluene. To several 450 ml. samples of the gasolinedescribed in Table II, 4.5 ml. of alkaline water bottoms and variousamounts of the Additive A toluene solution were added. Each sample wasagitated in a Waring Blendor as described in Example 1. A stable waterhaze was formed in the gasoline. Most of the samples cleared within sixhours, However, the water that separated out contained gasoline andvarious amounts of Additive A. Moreover, slight agitation (that whichcan be expected in the normal storage and transportation of gasoline)caused the formation of a stable water haze in the gasoline again.

It is thus seen that Additive A (an effective multipurpose additive)promotes the formation of a stable water haze in gasoline and thus aportion of the additive is lost from the gasoline by promoting anemulsion of Additive A and gasoline in water.

Example 3.Samples were prepared comprising 45 0 ml. gasoline (Table II),4.5 ml. alkaline water bottoms, Additive A (1.02 g./gal.), and AdditiveB (dodecylbenzene sulfonic acid-various concentrations in toluenesolution). Each sample was agitated as in the tests described in thepreceding examples. Most of the samples cleared within six hours,however, an emulsion of gasoline and Additive A in water remained at theinterface of the gasoline and water phases. Moreover, as in Example 2,mild agitation formed another stable water haze in gasoline that wasslow in disappearing. In short, Additive B used alone had little effectin promoting a complete separation of the gasoline and water.

Example 4 .--Samples were prepared comprising 45 0 ml. of gasolinecontaining 4.5 ml. of alkaline water bottoms, Additive A toluenesolution (about 90 lbs./ 1000 barrels), and various amounts of AdditiveC. Each sample was agitated as described in the preceding examples.

Most of the samples cleared after six hours, but an emulsion formed atthe interface. Moreover, mild agitation cause a haze to again form inthe gasoline.

The above examples show that Additive A (an effective multipurposeadditive) causes the formation of a haze in the gasoline and promotes agasoline and additive emulsion in water. The examples also show thatneither Additive B nor Additive C, used alone, obviates these problems.The following example illustartes the efiicacy of the additivecombination of this invention.

Example 5 .-'Several gasoline samples (similar to gasoline described inTable II) were prepared containing the following ingredients. The oilwas employed to dissolve the ingredients prior to blending with thegasoline.

Parts by weight Additive A 23.03 Additive B 1.59 Additive C 0.64 Solventoil (Table I) 74.74

This additive blend was added to 450 ml. samples of gasoline containing4.5 ml. alkaline water bottoms; the blend was added in various amounts,e.g. 0.875 to 0.2 g. per sample.

The samples were agitated in a Waring Blendor for one minute at 3600r.p.m.

The sample cleared within six hours (some within one hour). In contrastwith the results observed from the tests described in Examples 2 to 4:

(1) There was no emulsion at the interface or in the water phase.

(2) Mild agitation or the sample did not result in the formation of astable haze. The water was dispersed in the gasoline, but an immediateseparation was observed.

What is claimed is:

1. A multipurpose gasoline additive blend that does not significantlypromote a dispersion of water in gasoline; said blend consistingessentially of:

from to parts by weight of a multipurpose derivative of analkenylsuccinic anhydride having the following formula:

wherein R and R are selected from the group consisting of hydrogen andhydrocarbon radicals provided that at least one of said R and R is ahydrocarbon radical and the total number of carbon atoms in R and Rcombined is in the range of about 40 to 250; R is an aliphatichydrocarbon radical having in the range of 1 to 30 carbon atoms; n is 2to 3 and m is 0 to 10; and

from 10 to 5 parts by weight of the following combination:

an alkyl benzene sulfonic acid wherein the alkyl group contains in therange of from 1 to 30 carbon atoms; and

the reaction product of a polyalkylene glycol of a molecular weight inthe range of about 200' to 800 with an amber-colored viscous residuecontaining long chain polycarboxylic acids, having an acid numberbetween and 165, an iodine number of between 30 and 60, said residuebeing the nonvolatile material remaining from vacuum distilling at 270C. under 4 mm. Hg pressure, the by-product acids obtained in thepreparation of sebacic acid from castor oil by treatment with an alkali;

said alkyl 'benzene sulfonic acid constituting from 30 to 90 weightpercent of said combination of alkyl benzene sulfonic acid and reactionproduct.

2. An additive blend according to claim 1 wherein said alkyl group insaid alkyl benzene sulfonic acid contains from 8 to 16 carbon atoms.

3. An additive blend according to claim 1 wherein said alkyl benzenesulfonic acid is dodecylbenzene sulfonic acid.

4. An additive blend according to claim 1 wherein said polyal-kyleneglycol is polyethylene glycol.

5. An additive blend according to claim 1 wherein said blend isdissolved in a solvent selected from the class consisting of aliphaticsolvent oils and aromatic solvent oils.

6. An additive blend according to claim 1 wherein said benzene sulfonicacid constitutes from 45 to 75 Weight percent of the combination.

7. An additive blend according to claim 1 wherein the alkylene group insaid polyalkylene glycol has from 2 to 7 carbon atoms.

8. An improved gasoline to which has been added a minor amount of theadditive blend defined by claim 1 suflicient to inhibit the formation ofengine deposits.

9. An improved gasoline to which has been added suflicient of theadditive blend defined by claim 1 to impart to said gasoline from 1 to500 pounds of said alkenyl succinic anhydride derivative per 1,000barrels of gasoline.

10. An improved gasoline as defined by claim 9 wherein the alkyl benzenesulfonic acid in said additive blend is dodecyl benzene sulfonic acid.

10 I References Cited UNITED STATES PATENTS OTHER REFERENCES Esters byGlyco, published by Glyco Products, Inc., Brooklyn, N.Y., January 1954.

Polyethylene Glycol Esters, published by Kessler Chemical Co., Inc.,Philadelphia 35, Pa. Received in US.

15 Patent Office Dec. 20, 1948.

DANIEL E. WYMAN, Primary Examiner. I. E. DEMPSEY, Y. H. SMITH, AssistantExaminers.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,347,645 October 17, 1967 Gerhard J. Pietsch et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 8, lines 30 to 40, the formula should appear as shown belowinstead of as in the patent:

I H N(CH [NH(CH N N H 2 n 2 n m \C/ lc I'II \O 0 Signed and sealed this26th day of November 1968. (SEAL) Attest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER Attesting Officer Commissionerof Patents

1. A MULTIPURPOSE GASOLINE ADDITIVE BLEND THAT DOES NOT SIGNIFICANTLYPROMOTE A DISPERSION OF WATER IN GASOLINE; SAID BLEND CONSISTINGESSENTIALLY OF: FROM 90 TO 95 PARTS BY WEIGHT OF A MULTIPURPOSEDERIVATEIVE OF AN ALKENYLSUCCINIC ANHYDRIDE HAVING THE FOLLOWINGFORMULA: